Extracting metals from their ores



(No Model.)

J. A. KEATINGr 8v F. A. C. AMCO'I'TS.

EXTRAGTING METALS FROM THEIR ORES.

Trams/Eye.

NITED STATES ATENT Frio..

JOHN A. HEATING AND FREDERICK A. O. AIWIOOITS, OF RADERSBURG, MONTANA.

EXTRACTING METALS FROM THEIR ORES.

SPECIFICATION forming part of Letters Patent No. 548,994, dated October29, 1895.

Application filed November 1, 1894. Serial No. 527,662. (No specimens.)

To all whom it may concern.-

Beit known that we, JOHN A. KEATING and FREDERICK A. C. AMOOTTS, ofRadersburg, in the county of Jefferson and State of Montana, haveinvented a new and useful Improvement in Extracting Metals from theirOrcs, of which the following is a full, clear, and exact specification.

Our invention relates to improvements in extracting metals from theirores; andthe object of our invention is to produce a cheap, simple, andecient method of extracting gold and silver from their ores, andespecially from pyritic or other refractory ores. The

method may also be used to advantage in working concentrates to effectthe separation of metals.

To this end our invention consists of a method of extracting metals fromtheir ores which will be hereinafter described and claimed.

In carrying out our invention the raw ore is ground in a suitable mill,with quicksilver and a solution of acetic acid or acetate of sodium, toa neness of not less th an one-hundred mesh, thus causing the gold andsilver to be thoroughly incorporated and amalgamated with thequicksilver.

In carrying out our invention we use one pound of acetic acid oracorresponding equivalent of acetate of sodium to twenty-four gallons ofwater. By the action of this reagent the evil effects of sulphur andcertain gangues contained in pyritic and other base gold-bear# ing oresare counteracted, the quicksilver is kept clean and active, and theamalgamation is largely effected while the ore and solution aretogether. We are aware that acetic acid has been heretofore used inpreparing ores for future amalgamation, and we make no claim to suchstep broadly.

The grinding or crushing of the ore in the presence of the acetic acidand quicksilver effects not only a thorough mechanical admixture of thereagents, but the aceticacid bath thoroughly saturates the ultimateparticles of the ore and enables the quicksilver to take hold of andamalgamate the gold andv silver. After this step of the operation iscomplete, the solution is then drawn 0E into a settling tank, where,after it settles, it is pumped back into a standardizingtank, and whenit is standarized it is used over again.

When the solution is drawn off from the mill, clear water is introducedand the pulp flowed off into a series of settling-tanks until the gangueor waste rock is all driven olf and nothing but the gold and silverbearing pulp remains. The pulp is then drawn from the bottom of thevarious tanks into an amalgamating-pan and with clear water is agitatedwith a muller till the entire residue of gold, amalgam, and flouredquicksilver is caught on the copper plates of the pan-bottom. A solutionof concentratedlye or cyanide of potassium may be added to the solutionto promote amalgamation on the copper plates of the pan-bottom, the lyeor potassium acting in the usual way to clean the Quicksilver.

Figure 1 is a side elevation of an apparatus for carrying out ourprocess, and Fig. 2 is a plan view of the two settling-tanks.

A is a tank in which the acetic-acid soluy tion is mixed andstandardized.

B is the solution-supply tank, which is fed from A at intervals througha valved pipe and discharges continuously through a valved pipe a: intothe mortar or stamp-trough O of a stamp-mill or other crushing,grinding, or comminuting apparatus. The raw ore is fed through hopper D.In the bottom of the mortar or trough C is placed the requisite quantityof quicksilver. The ore that is crushed fine in the presence of theacetic-acid solution and quicksilver passes out of the mortar throughthe screens, or through theplace of discharge in any sort ofgrinding-mill, and the solution or liquid that escapes with the ore willbe carried through the sluice E to one of two settling-tanks F or F',with either of which sluice E may be connected. When one of these tanksF is full of pulp, the sluice will be changed to the other tank F andthe solution drawn out of the disconnected tank after the pulp hassettled. This solution and all the overflow solution, while the tanksare being iilled, will be conveyed by a sluice (not shown) to someconvenient point and thence pumped into tank A and standardized for useagain. After tank F has been filled with settled pulp and the solutionall drawn 0E, clear water is introduced into tank'F to flow IOC o thewaste rock, 85o. The residue of pulp containing the metals will be drawnout through a pipe into the amalgamating-pan G. The sluiceE is againconnected to tank F, and tank F is Washed and discharged of its contentsin a similar manner.

To help the* discharge of the tanks F and F and the Washing of thecontents, and {iowing o of the Waste rock, Water is introduced throughfive one-half-inch pipes p, Fig. 2, which open through the bottom of thetanks F and F', and these pipes are provided each with upwardly-openingcheck-valves to prevent the pulp from passing down them. Through thesepipes Water under pressure is introduced.

The arnalgamating-pan Gr, in Which the amalgamation of the preciousmetals with the quicksilver is completed,l1as copper sides and bottom,with a revolving stirrer having four arms rotating about twelve tofifteen times a minute. Each arm has shoes on it, made of Wood, whichrun as close as possible to the bottom Without touching it. This panalso has overflow-holes h `in its sides and a quicksilver-Siphon s.

Having thus described our invention, what We claim as new, and desire tosecure by Letters Patent, is-

The process herein described of extracting gold and silver from theirores which consists in comminuting the ores in the presence ofquick-silver in a solution of acetic acid or its described equivalent,then drawing oi the solution into a settling tank and standardizing itfor use again, then iiowing od by clear water the lighter portions ofthe pulp containing the gangue or waste rock and nally removing theheavy pulp containing the precious metals and completing theiramalgamation and recovery7 substantially as shown and described.

JOHN A. KEATING. FREDERICK A. C. AMGOTTS.

Witnesses to the signature of John A. Keating:

FRANK WELLS, G. B. CLARKE.

Witnesses to the signature of Frederick A. C. Amcotts:

WARREN B. HUToHiNsoN, JNO. M. RITTER.

